Weight-correction formula for maternal serum screening for Down syndrome in Taiwan

Background and purpose: This study examined the relationship between matern al weight and serum marker concentrations (alpha-fetoprotein [AFP] and huma n chorionic gonadotropin [hCG]) to develop a weight-correction formula for second-trimester Down syndrome screening in Taiwan. Methods: We conducted a prospective observational study based on data from 18, Down syndrome 016 pregnant Taiwanese women who participated in a second -trimester Down second trimester syndrome screening program at Taiwan Adven tist Hospital. The relationship between I maternal serum maternal weight an d the multiple of median (MoM) concentrations of serum markers alpha-fetopr otein was analyzed using two methods; one involved all the observational da ta (all point human chorionic method), while the other involved only the me dian concentrations at various gestational ages (median regression method). In each method, several statistical approaches were used, including simple -linear, reciprocal, quadratic, and log-transformation linear regression. Results: The correlation between maternal body weight and serum marker conc entrations using the all point regression method was very poor, while the m edian regression method achieved a good fit. The reciprocal regression anal ysis had the best fit between AFP MoM concentration and maternal weight, wh ile the best fit between hCG MoM concentration and maternal weight was achi eved with quadratic regression analysis. Conclusion: The present study has developed a race-specific weight-correcti on formula for Taiwanese women. This formula is expected to be helpful in s econd-trimester Down syndrome screening programs in Taiwan.